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Abstract Turf provides an irreplaceable surface for recreational and sport activities in urban landscape. Sand-based rootzone is recommended for turf establishment because of its excellent compaction resistance. It is necessary to improve the water and nutrient retention of sand-based rootzone by soil amendments in maintaining healthy turf. The objective of this research was to evaluate the effects of rice-husk biochar on sand-based rootzone amendment and creeping bentgrass (Agrostsis stolonifera) establishment. The results showed that bulk density was linearly decreased in proportion to rice-husk biochar. Total porosity and capillary porosity, water retention, and saturated hydraulic conductivity were significantly increased in proportion to rice-husk biochar. Sand-based rootzone amended with 10% of rice-husk biochar promoted the seed germination and young seedling growth with the significantly higher growth rate, leaf emergence rate, shoot and root biomass, and turf coverage than the control. These results indicate that rice-husk biochar had superior characteristics to previous reported biochars in the sand-based rootzone amendment and could be used to improve soil physical properties and turf healthy in sports and recreation playgrounds. [ABSTRACT FROM AUTHOR]

Flutolanil and pentachloronitrobenzene (PCNB) are fungicides used to control or suppress foliar and soil borne diseases in turf and ornamental crops. On golf courses, sports fields, sod farms and commercial lawns these fungicides are used as preventive treatments to combat snow mold, brown patch and fairy ring. Depending on the aquatic organism, flultolanil and PCNB are considered to be moderately to highly toxic. Therefore runoff or drift from treated areas may be hazardous to organisms in adjacent aquatic sites. This research compared the transport of flutolanil and PCNB with runoff from turfgrass managed as a golf course fairway. The quantity of fungicide transported with runoff and observations reported with the chemographs followed trends in agreement with the chemical properties of the compounds. Overall, we observed the rate of transport for flutolanil was greater than PCNB, which contributed to the more than 12 times larger load (µg/m 2 ) of flutolanil transported off-site at the conclusion of the simulated storm runoff. A better understanding of the off-site transport of pesticides with runoff is needed to make informed decisions on management practices to reduce potential adverse effects on non-target organisms, as well as maintain control of targeted pests in the area of application. In addition, data obtained with this research can be used in model simulations to predict nonpoint source pollution potentials beyond experimental conditions. [ABSTRACT FROM AUTHOR]

Creeping bentgrass ( Agrostis stolonifera ), an important turfgrass on golf course putting greens can become plagued by bacterial etiolation disease caused by Acidovorax avenae subsp. avenae ( Aaa ). There are no known pesticides that have been shown to be effective in managing this disease. This series of hydroponic growth chamber studies investigated whether pre-treating plants with SA or JA could be effective in reducing disease symptoms of Aaa in creeping bentgrass ‘Penn-A4’ ( Aaa sensitive) and ‘Tyee’ (more tolerant). The treatments included foliar application of 10 μmol/L SA, 20 μmol/L SA, 0.5 mM JA in 0.02% ethanol and 2 mM JA in 0.02% ethanol prior to exposure to heat stress (35 °C) and optimal temperature (23 °C) with or without Aaa inoculation. Physiological measurements included turf quality (TQ), leaf and root electrolyte leakage, chlorophyll content (CHL), photochemical efficiency and root viability. No significant differences were detected in either cultivar due to chemical or heat treatment alone, which indicates chemical treatments had specific effects on plant responses to bacteria and were not confounded by plant heat stress symptoms. SA application reduced Aaa disease symptoms of both cultivars under both optimal and high temperature treatments. At both 23 °C and 35 °C, the severity of disease in plants treated with SA was less than in control plants based on all measurements in our experiment. Creeping bentgrass ‘Tyee’ treated with JA showed significantly higher TQ than control plants at 35 °C. ‘Penn-A4’ treated with JA only showed significantly higher CHL than control at 23 °C. SA and JA treatments could be viable methods to induce creeping bentgrass tolerance of bacterial pathogens; however, field testing of these methods is needed. [ABSTRACT FROM AUTHOR]

Efficacy of foliar applied fungicides following simulated rainfall for the control of dollar spot (caused by Sclerotinia homoeocarpa F.T. Bennett) was assessed in a two-year field study on creeping bentgrass ( Agrostis stolonifera L.) turf maintained as a golf course fairway. The study was conducted as a randomized complete block design with a factorial arrangement. Fluazinam (0.8 kg a.i. ha −1 ), chlorothalonil (3.79 kg a.i. ha −1 ) or iprodione (1.5 kg a.i. ha −1 ) were applied, then subjected to simulated rainfall (2.54-mm) at intervals of 15-, 30-, 60-min post-application, or no simulated rain. In most cases, simulated rainfall occurring ≤60 min post-application had greater disease than no rain plots; however, few differences occurred among rainfall intervals ≤60 min. Fluazinam provided the greatest dollar spot reduction regardless of simulated rainfall interval throughout the study. Chlorothalonil was most susceptible to losses in efficacy due to simulated rainfall, resulting in the greatest disease incidence of those fungicides evaluated. Iprodione was comparable to chlorothalonil during high disease pressure, although during moderate disease pressure it controlled dollar spot for approximately 7 days before disease increased in plots receiving simulated rain compared to those without simulated rain. These data demonstrate that efficacy of fungicides applied for dollar spot control are affected by rain, and differ in their ability to control disease following post-application rain events. Fluazinam, a recently introduced contact fungicide for use on turfgrass, can provide improved control compared to chlorothalonil or iprodione when rain is eminent. [ABSTRACT FROM AUTHOR]

Preventive, watered-in applications of DMI fungicides provide control of several soilborne turfgrass diseases on golf putting greens. The objectives of this two-year field study were to determine the impact of these applications on foliar diseases, and evaluate the impact of application timing of paclobutrazol, a plant growth regulator, on disease severity and turfgrass quality. Triadimefon (1.58 kg a.i. ha −1 ), tebuconazole (0.82 kg a.i. ha −1 ), metconazole (0.43 kg a.i. ha −1 ), and triticonazole (0.64 kg a.i. ha −1 ), were applied twice in late April and May and immediately watered in to the soil profile with 5 mm of post application irrigation. Paclobutrazol (0.28 kg a.i. ha −1 ) was applied alone, in a tank-mix with the fungicide application, 7 days or 14 days after the fungicide application. Overall dollar spot severity, assessed as area under the disease progress curve (AUDPC), was significantly lower in fungicide treated plots than non-treated plots in both trial years. The date of threshold symptom observation (≥5 infection centers per plot), however, was not different between fungicide treated and non-treated plots in 2011. Triadimefon treated plots had lower AUDPC values than other fungicide treatments. Brown patch severity was not significantly different among treatments. Paclobutrazol applied alone did not reduce dollar spot or brown patch severity, however, paclobutrazol + fungicide treatments resulted in lower dollar spot severity than plots treated with fungicide alone. Short-lived phytotoxicity (bronze discoloration) was observed in plots treated with triadimefon or paclobutrazol + fungicide. Spring preventive fungicide applications targeted at soilborne disease control also provided residual control of dollar spot in this study. [ABSTRACT FROM AUTHOR]

Bacterial etiolation, caused by Acidovorax avenae and Xanthomonas translucens , has become a widespread problem in turfgrass throughout the U.S. Various management tactics are used in managing this disease and differ among turfgrass managers. The use of biostimulants and trinexapac-ethyl (TE) has become a staple in putting green management and many products have been associated with etiolation outbreaks. Experiments performed in field and controlled environments evaluated the impact of commercial biostimulants and TE on etiolation of creeping bentgrass ( Agrostis stolonifera L. c.v. ‘Penn A-1’) caused by both A. avenae and X. translucens. In the field, a factorial study was arranged as a split-plot randomized complete block design with 4 replications. The main plot consisted of biostimulants (Knife Plus, CytoGro, Astron, Nitrozyme, PerkUp, BioMax, and none) applied at label rates while the subplot treatments consisted of TE application frequency (0.049 kg ha −1 applied at 7 d, 14 d, and none). For controlled environment experiments, biostimulant and TE treatments were arranged in a randomized complete block design with 4 replications. Bacterial etiolation was measured regularly when present using a grid count to determine the percent area exhibiting etiolation in the field while etiolated turfgrass plants were counted individually in controlled environments. Turf quality was also rated using a scale of 1–9 with 1 = completely dead, 9 = best, and 5 = minimum acceptable turf quality for all experiments. Biostimulant treatments did not have a significant effect on etiolation caused by either bacterium. Trinexapac-ethyl decreased etiolation caused by X. translucens and increased etiolation caused by A. avenae. These results support the necessity of identifying bacteria associated with etiolation as variable effects were observed with TE treatments. These factors should be considered when developing plant growth regulator programs if etiolation is problematic. Future research to evaluate phytohormone production in these bacteria may improve our understanding of etiolation development while improving methods for control. [ABSTRACT FROM AUTHOR]

The article presents a study which determines the ability of TurfPQ model to accurately predict the transport of pesticides with runoff following more intense precipitation. It was conducted with creeping bentgrass turf which is managed as a golf course fairway. Using rainfall simulator, controlled rainfall simulations were taken to deliver water droplets the same with the natural rain. A mixture of pesticides which contain dicamba, 2,4-D, mecoprop-p (MCPP), flutolanil and chlorpyrifos was applied to six adjacent 24.4 by 6.1 meter plots. It was found out that predictions of MCPP were close with various overpredictions which were observed in MCPP and 2,4-D. Dicamba, flutolanil and chlorpyrifos predictions were underestimated consistently. Moreover, dicamba was seriously under predicted.

In this paper we present some aspects concerning the chorology, floristic composition, syn-ecology, and dynamics of the alluvial and lowland hay meadows in the River Timiş basin. Agrostis stolonifera dominates depression areas with high moisture for the entire year, while meadows of Alopecurus pratensis can be found on plane lands that are moist in spring and drier in summer. Lowland hay meadows with Arrhenatherum elatius are fragmentary and are met on the flooding plain terraces and on slightly sloppy lands. On moister lands, not cultivated recently, around the villages, there are frequent coenoses edified by Elymus repens, together with Agrostis stolonifera and numerous species considered weeds. [ABSTRACT FROM AUTHOR]

Summary: The objective of this study was to determine effects of elevated CO2 and soil nutrient availability on growth and plant tissue quality in four grass species, Agrostis stolonifera, Anthoxanthum odoratum, Festuca rubra and Poa pratensis, native in Western European calcareous grassland. Plants were grown for 65 days in the greenhouse in pots with untreated soil from calcareous grassland under ambient (350 ppm) and elevated (700 ppm) CO2 either with or without fertilisation. In general, elevated CO2 increased plant height, total biomass, starch and sugar concentrations, and decreased water and nitrogen concentrations. However, the response to CO2-enrichment depended strongly on the grass species investigated. Fertilisation enhanced most effects of elevated CO2. Biomass production in fertilised plants increased more under elevated CO2 than in unfertilised plants whereas leaf nitrogen concentration of fertilised plants decreased more at elevated CO2 than it did in unfertilised plants. Furthermore, a species-specific response to elevated CO2, depending on soil nutrient availability was detected in starch and sugar concentrations (three-way interaction). The data from this study indicate that grass species vary in their response to elevated CO2 in biomass production and tissue quality. Furthermore, increasing nutrient availability can substantially alter effects of elevated CO2. Since the investigated grass species are important larval food-plants of insect herbivores on calcareous grassland, the observed species-specific reactions to CO2-enrichment and high nutrient availability in tissue quantity and quality are discussed with respect to their effects on insect performance and thus abundance and biodiversity of these insects. In der vorliegenden Studie wurde der Effekt von erhöhtem CO2 und dem Nährstoffangebot im Boden auf das Wachstum und die Blattqualität von vier Trockenrasen Grasarten (Agrostis stolonifera, Anthoxanthum odoratum, Festuca rubra und Poa pratensis) untersucht. Die Gräser wurden in einem unbehandelten Boden eines Trockenrasens während 65 Tage im Gewächshaus angezogen. Die Pflanzen wurden unter normalen (350 ppm) und erhöhten (700 ppm) CO2-Bedingungen, mit oder ohne Düngung kultiviert. Im Allgemeinen hatten erhöhte CO2-Bedingungen einen positiven Effekt auf die Pflanzenhöhe und -gewicht, Stärke- und Zuckerkonzentration und einen negativen Effekt auf den Wasser- und Stickstoffgehalt des Blattgewebes. Dieser CO2-Effekt war stark von der Grasart abhängig und wurde durch die Düngung verstärkt. So erhöhte sich die Biomasse von gedüngten Pflanzen unter erhöhten CO2-Bedingungen stärker als bei nicht gedüngten Pflanzen. Hingegen nahm der Stickstoffgehalt der Gräser durch die Düngung unter erhöhten CO2- Bedingungen stärker ab als bei nicht gedüngten Pflanzen. Zusätzlich konnte eine artspezifische Reaktion auf CO2-Erhöhung in Abhängigkeit vom Nährstoffangebot im Boden für den Gehalt von Stärke und Zucker gefunden werden. Die Daten der vorliegenden Studie zeigen, dass der Effekt von erhöhten CO2-Bedingungen auf Wachstum und Blattqualität von der Grasart abhängig ist. Zusätzlich kann der CO2-Effekt durch das Nährstoffangebot im Boden beeinflusst werden. Da die untersuchten Grasarten wichtige Futterpflanzen für pflanzenfressende Insekten sind, könnten diese artspezifischen Reaktionen einen Effekt auf die Entwicklung der Insekten und somit auf deren Vorkommen und Artenvielfalt haben. [Copyright &y& Elsevier]

The article presents information about transgenes. Transgenes can end up in unmanaged ecosystems inevitably if a multitude of novel traits is inserted into numerous species at multiple locations on Earth. This idea has been supported by two recent publications. According to one of them, when transgenes were inserted in turf grass namely creeping bent grass or agrostis stolonifera (A.S.), it ended up in wild A.S. populations growing in non-agronomic habitats. The next publication pertains to the fate of crop genes after four years of hybridization.

The control of dollar spot by paclobutrazol applied as a growth regulator on a creeping bentgrass (Agrostis palustris) and annual bluegrass (Poa annua) fairway turf was compared with two standard fungicide treatments in Minnesota during two growing seasons. Paclobutrazol wasapplied every 3 weeks, staggered by about 10 days with fungicide treatments (chlorothalorlil or propiconazole), also applied every 3 weeks. Paclobutrazol alone significantly reduced the number of dollar spot infection centers during both summers, often by as much as 80%. Chlorothalonil or propiconazole were usually more effective in controlling dollar spot than paclobutrazol. Paclobutrazol improved disease control by fungicides when tested in combination with various rates of chlorothalonil or propiconazole. Paclobutrazol applied as a growth regulator could thus be used to reduce the base line severity of dollar spot of turf. [ABSTRACT FROM AUTHOR]

Although scientists have found little transport of nutrients to datein runoff from turfgrasses, more research is needed on a wider rangeof soil conditions and management scenarios. This study was designedto assess nutrient and sediment transport from creeping bentgrass (Agrostis palustris Huds.) and perennial ryegrass (LoJium perenne) turfs and to assess the influence that vertical mowing had on sediment transport. Sloped plots of bent grass and ryegrass, maintained similar to a golf fairway, were irrigated to force runoff for the generation of runoff and leachate water samples. About 12 h before each runoff event, irrigation was used to equilibrate soil moisture for all plots.For four events, plots were treated with fertilizer at a rate of 4.9g N m-2, 0.3 g P m-2, and 4.1 g K m-2 about 4 h after pre-event irrigation and 8 h before runoff. For another four events, plots were vertical 6 h before runoff. Water samples were analyzed for NO3-N, total Kjeldahl-N (TKN), phosphate, and sediment. Mean N03-N concentrations rarely exceeded 1 mg L-1. Phosphate and TKN concentrations and losses significantly increased when runoff was forced 8 h after fertilization. On average for these events, 11% of applied P and 2% applied N was detected in runoff and 14% applied P and 3% applied N was detected inleachate. For all other events, nutrient concentrations and losses were consistently lower. Vertical mowing had little affect on sedimenttransport. Sediment transport from both turfs averaged 0.8 kg ha-1. On golf fairways, off-site movement of nutrients may happen if runoff occurs soon after granular fertilizer is applied to a nearly saturated soil." [ABSTRACT FROM AUTHOR]